There have been developed a wide variety of prefabricated panels or the like for multiple uses including building structures One eminently successful type of prefabricated panel is plywood. There have also been developed a variety of sandwich structures having, for example, a honeycomb core.
In the construction of buildings various types of preformed panels have been employed and in the field of concrete buildings, it is known, for example, to pour large concrete panels which generally have reinforcing steel therein and may have other materials, such as insulation included therein, for use as walls, floors and the like. Many attempts have also been made to form panels from a wide variety of plastic materials. It is known, for example, to employ foamed plastics in combination with structural elements for improved insulating properties.
The production of structures from heat exapndable plastic materials, such as pelletized polystyrene, is known to suffer from the limitations that it is not possible to maintain final overall dimensions equal to mold dimensions. Such materials are normally expanded by heat in a mold to thus fill the mold with a substantially homogeneous material, however, this material is also known to shrink after removal from the mold. The prior art attempts to attain desired final overall dimensions of structures formed in this manner include estimating the degree of shrinkage and expanding the mold by such an amount. Clearly this approach provides only an approximation of the desired final dimensions.
The present invention produces a panel having an expanded plastic core of sheet-like configuration with thin reinforcing strips bonded to front and back surfaces thereof, at least only the edges of the core. This panel has a variety of uses and may be particularly advantageously employed by attaching a wire mesh to one surface in spaced relation thereto for receiving concrete. Panels in accordance with the present invention may be joined together to form a desired shape or structure, and with the above-noted wire mesh on the outer surface thereof, concrete may then be applied to produce a structurally sound building or the like wherein the panels of the present invention form an integral part thereof.